Roof repair drone

ABSTRACT

An aerial drone for repairing holes or punctures in a membrane on a roof, wherein the aerial drone includes at least one camera for recording a section of the membrane, a 3D printer adapted to print onto the section of the membrane, wherein the 3D printer is controllable wirelessly from a different altitude and/or the ground.

The present invention describes an aerial drone for repairing holes orpunctures in a membrane on a roof, a system for repairing holes orpunctures in a membrane on a roof, and a method for repairing holes orpunctures in a membrane on a roof.

Flat roofs are commonly waterproofed against the penetration of water byusing prefabricated thermoplastic single- and multi-ply membranes, whichare most often based on TPOs (thermoplastic olefins), PVC, or EPDM. Analternative to such prefabricated membranes are liquid applied membranes(LAMs) which are based on 1-component or 2-component reactivecompositions. Liquid applied membranes, e.g. on the basis ofpolyurethanes (PUs) or silicones, cure after their application in orderto gain their final physical properties. Due to age, accidental damages,or harsh environmental conditions such as hailstorms, waterproofingmembranes may become punctured and have holes, which should be repairedin order to ensure the waterproofing properties of the membrane.

Currently, holes in PVC roofs can be repaired by patching the damagedarea with new membrane welded over the damaged area. To do so, a workerneeds to climb on the roof.

One major problem associated with repairing roofs is the risk of injuryto workers on the roof. According to OSHA(https://www.osha.gov/oshstats/commonstats.html), 384 of the deaths inthe construction industry in 2016 were as a result of falls. Andaccording to Dong et al. (Journal of safety research 44, 2013, 17-24),one third of fatal falls in the construction industry are roof falls.Therefore, reducing the need for workers to go on to roofs will decreasethe risk of falling and hopefully reduce the number of deaths andinjuries caused by roof falls.

Therefore, it is an object of the present invention to provide means forrepairing holes or punctures in a membrane on a roof, which reduce theneed for workers to be on roofs and which automate the roof repair andmaintenance process.

The object is solved by an aerial drone for repairing holes or puncturesin a membrane on a roof, characterized in that the aerial dronecomprises at least one camera for recording a section of the membraneand a 3D printer adapted to print onto the section of the membrane,wherein the 3D printer is controllable wirelessly from a differentaltitude and/or the ground.

The present invention provides an unmanned aerial drone (such as anoctocopter) that carries a tool that can be controlled remotely andoperated to repair small holes or punctures in the membrane on a roof.The tool that is carried is a 3D printer, for example a fused depositionmodeling (FDM) 3D (three-dimensional) printer capable of printingdirectly onto the surface of the roof. Aerial drones are well known inthe art and the basic setup of the aerial drone does not need to beexplained here. The aerial drone, respectively the drone, of theinvention comprises elements and functions of commercially availableaerial drones. However, the aerial drone of the invention additionallycomprises features and components named in claim 1. The invention allowsrepairs to be performed remotely from the safety of the ground, orautomatically performed by an autonomous drone capable of detectingdamage and depositing a patch to repair the membrane on the roof.

The explanations, embodiments, and advantages of specific embodimentsexplained for the aerial drone according to the invention also relate tothe system according to the invention and to the method according to theinvention and vice versa, unless something else is clear from thedescription.

Preferably, the 3D printer is attached to the bottom (side) of theaerial drone. Preferably, the 3D printer is attached to the bottom(side) of the aerial drone such that the 3D printer is centered betweenthe legs of the drone in landing position.

In specific embodiments, the at least one camera for recording a sectionof the membrane is adapted to record after landing of the aerial droneon the membrane on the roof.

In specific embodiments, the at least one camera for recording a sectionof the membrane is adapted to record only after landing of the aerialdrone on the membrane on the roof.

For an effective use of the 3D printer, it is necessary to record thesection of the membrane with holes or punctures. Based on therecordings, the aerial drone can control the printing itself or printunder external control.

In specific embodiments, the at least one camera for recording a sectionof the membrane is adapted to be part of the aerial drone's flightsystem. This means the recordings of the camera are used for flying ofthe aerial drone and/or directing the aerial drone's movement.

Preferably, the section of the membrane onto which the 3D printer isadapted to print, is the section of the membrane with holes orpunctures.

In preferred embodiments, the at least one camera for recording asection of the membrane is adapted to record a section of the membraneon the roof between the legs of the drone in landing position.

In specific embodiments, the at least one camera for recording a sectionof the membrane is adapted to be focused on a level corresponding to alevel on which the distal ends of the legs of the aerial drone are inlanding position.

In specific embodiments, the at least one camera for recording a sectionof the membrane is adapted to record the membrane during flight of theaerial drone. This embodiment is useful to detect holes or punctures ina membrane on a roof using the aerial drone.

In specific embodiments, the at least one camera for recording a sectionof the membrane is one camera.

This embodiment saves weight, which allows a longer flight time for theaerial drone and/or saves weight for other features.

In preferred embodiments, the 3D printer is controllable wirelessly froma different altitude and/or the ground.

In preferred embodiments, the 3D printer is controlled wirelessly from adifferent altitude and/or the ground.

Further embodiments are described in the dependent claims.

In specific embodiments, the aerial drone comprises at least oneon-board communication unit, wherein the at least one on-boardcommunication unit is adapted to wirelessly receive commands for the 3Dprinter from a ground based communication unit and optionally totransfer the commands to the 3D printer. The on-board communication unitallows that the 3D printer can be controlled from a ground basedcommunication unit. The on-board communication unit preferably is anintegral component of the 3D printer or more preferably is a separatecomponent that transfers the received commands via a link, e.g. a cable.

In specific embodiments, the aerial drone comprises at least oneon-board communication unit, wherein the at least one on-boardcommunication unit is adapted to receive recordings from the at leastone camera and to wirelessly send the recordings to a ground basedcommunication unit. The at least one on-board communication unit allowsthat recordings from the at least one camera can be sent to a groundbased communication unit. Thus, the section of the membrane can beobserved before, during, and after printing.

In specific embodiments, the aerial drone comprises at least oneon-board communication unit, wherein the at least one on-boardcommunication unit is adapted to wirelessly receive commands for the 3Dprinter from a ground based communication unit and optionally totransfer the commands to the 3D printer and wherein the at least oneon-board communication unit is adapted to receive recordings from the atleast one camera and to wirelessly send the recordings to a ground basedcommunication unit. The combination of these features allows a goodcontrol and observation of the membrane and the printing process fromthe ground based communication unit.

In specific embodiments, the at least one camera for recording a sectionof the membrane is one camera and the at least one on-boardcommunication unit is one on-board communication unit. In specificembodiments, the at least one on-board communication unit is oneon-board communication unit.

These embodiments save weight, which allows a longer flight time for theaerial drone and/or saves weight for other features.

In preferred embodiments, the at least one camera for recording asection of the membrane is adapted to provide recordings to the at leastone on-board communication unit.

In preferred embodiments, the 3D printer is a fused deposition modeling3D printer.

In preferred embodiments, the 3D printer is a fused deposition modeling3D printer capable of printing using a filament or capable of printingusing pellets. In specific embodiments, the 3D printer is a fuseddeposition modeling 3D printer capable of printing using a filament. Inspecific embodiments, the 3D printer is a fused deposition modeling 3Dprinter capable of printing using pellets. In specific embodiments, thefused deposition modeling 3D printer is a pellet extruder.

In preferred embodiments, the 3D printer is a fused deposition modeling3D printer, which is controllable wirelessly from a different altitudeand/or the ground. In preferred embodiments, the 3D printer is a fuseddeposition modeling 3D printer, which is controlled wirelessly from adifferent altitude and/or the ground. A fused deposition modeling 3Dprinter is light and suitable to directly print from its nozzle onto asurface such as the membrane. The nozzle can be moved swiftly in orderto print on a larger portion of the section.

In preferred embodiments, the 3D printer is capable of printing directlyonto the surface of the roof. In preferred embodiments, the nozzle ofthe 3D printer is capable of printing directly onto the surface of theroof.

In preferred embodiments, the aerial drone respectively the 3D printercomprises printing material.

The term “filament” is known in the art and describes printing materialthat is used by a fused deposition modeling 3D printer in order toprint. A pellet extruder can be used as fused deposition modeling 3Dprinter. Such pellet extruders and pellets are well known in the art andpellets are printing material that can be used by the fused depositionmodeling 3D printer in order to print. The printing material is fed intothe hot end respectively nozzle of the fused deposition modeling 3Dprinter and runs molten from the nozzle on the surface to be printed.

In specific embodiments, the aerial drone respectively the 3D printercomprises at least one filament (as printing material). The filament isadapted to be fed into the hot end respectively nozzle of the fuseddeposition modeling 3D printer. The filament is preferably stored on aspool. Preferably the filament is a flexible filament. Preferably thefilament is a flexible filament, which is stored on a spool. Preferably,the filament is of a thickness of 1.25 mm to 3.5 mm.

Flexible filaments, which can be stored on a spool, save space on theaerial drone.

In specific embodiments, the aerial drone respectively the 3D printercomprises pellets (as printing material).

In specific embodiments, the aerial drone respectively the 3D printercomprises printing material, wherein the printing material preferablycontains polyvinyl chloride and/or polyurethane and/or thermoplasticolefin and/or ethylene propylene diene monomer rubber and/or bitumen.Polyvinyl chloride and/or polyurethane and/or thermoplastic olefinand/or ethylene propylene diene monomer rubber and/or bitumen iscompatible with the material of liquid applied membranes and haswaterproofing properties.

In specific embodiments, the aerial drone respectively the 3D printercomprises printing material, wherein the printing material preferablycontains polyvinyl chloride and/or polyurethane and/or thermoplasticolefin and/or ethylene propylene diene monomer rubber and/or bitumenand/or PLA (Polylactide).

In specific embodiments, the aerial drone respectively the 3D printercomprises printing material, wherein the printing material preferablycontains polyvinyl chloride and/or polyurethane and/or thermoplasticolefin and/or ethylene propylene diene monomer rubber and/or bitumen.

In specific embodiments, the aerial drone respectively the 3D printercomprises printing material containing polyvinyl chloride and/orpolyurethane. In specific embodiments, the printing material containingpolyvinyl chloride and/or polyurethane is heat stabilized up totemperatures of 300° C. or 280° C.

It has been found that temperatures of 190° C. to 300° C., preferably210° C. to 260° C., are required at the hot end of the 3D printer inorder to print using (flexible) filaments from polyvinyl chloride. Ithas been found that heat stabilization allows printing using (flexible)filaments from polyvinyl chloride by prevention of thermal degradation.

In specific embodiments, the aerial drone comprises several printingmaterials, optionally containing different materials.

The verb “to contain” and its conjugations include the verb “to consistof” and its conjugations. The verb “to comprise” and its conjugationsinclude the verb “to consist of” and its conjugations.

In specific embodiments, the aerial drone has a weight of 1 kg to 25 kg,preferably 4 kg to 16 kg, more preferably 7 kg to 13 kg, most preferably9 kg to 12 kg. The inventors have prepared an aerial drone that cansolve the technical problem, i.e. an aerial drone for repairing holes orpunctures in a membrane on a roof. Surprisingly, the number ofcomponents and the sum of the weight of all components was successfullyminimized to the given weight range. As a result, the aerial drone withall its features (and tools) has a weight, which can be driven by abattery for a sufficient operation/flight time.

In specific embodiments, the aerial drone comprises at least one batteryunit with a sum of electric charge of 14000 mAh to 30000 mAh, preferably19000 mAh to 27000 mAh, for providing power to at least one motor of thedrone. The sum of electric charge of 14000 mAh to 30000 mAh, preferably19000 mAh to 27000 mAh, describes how much electric charge is availablefrom the battery respectively all batteries of the aerial drone fordriving the motor respectively all motors of the aerial drone. Thiselectric charge preferably refers to the electric charge available tothe at least one motor of the drone, and not to the 3D printer, cameraetc. The inventors have prepared an aerial drone that can solve thetechnical problem, i.e. an aerial drone for repairing holes or puncturesin a membrane on a roof. The inventors have found the optimal electriccharge required to drive the aerial drone, which is a compromise betweena too heavy but powerful battery and a light but insufficient battery.As a result, the aerial drone with all its features (and tools) can bedriven by a battery with an optimal weight for a sufficientoperation/flight time.

In specific embodiments, the aerial drone has a weight of 1 kg to 25 kg,preferably 4 kg to 16 kg, more preferably 7 kg to 13 kg, most preferably9 kg to 12 kg, and the aerial drone comprises at least one battery unitwith a sum of electric charge of 14000 mAh to 30000 mAh, preferably19000 mAh to 27000 mAh, for providing power to at least one motor of thedrone. The sum of electric charge of 14000 mAh to 30000 mAh, preferably19000 mAh to 27000 mAh, describes how much electric charge is availablefrom the battery respectively all batteries of the aerial drone fordriving the motor respectively all motors of the aerial drone. Thiselectric charge preferably refers to the electric charge available tothe at least one motor of the drone, and not to the 3D printer, cameraetc. As a result, the aerial drone with all its features (and tools) hasa weight for which the electric charge of the battery is optimal for asufficient operation/flight time.

In specific embodiments, the at least one on-board communication unit isa microcomputer, preferably a single-board computer or a Raspberry Pi,with an operating system, preferably Octoprint, installed. If the atleast one on-board communication unit and the 3D printer are not oneintegral component, the at least one on-board communication unit isconnected to the 3D printer, preferably via USB cable.

A microcomputer, such as a single-board computer or a Raspberry Pi, isvery light, requires little space and can be easily attached to theaerial drone. Further, these require only a small and light battery,which further reduces the weight of the aerial drone.

In specific embodiments, the at least one on-board communication unit isa single-board computer.

In specific embodiments, the at least one on-board communication unit isone on-board communication unit and the sum of the weight of theon-board communication unit and of all cameras for recording the sectionof the membrane is 1 g to 300 g, preferably 1 g to 150 g, mostpreferably 1 g to 80 g. This setup further reduces the weight of theaerial drone. Few connecting parts or other heavy and expensive imagingcomponents are required.

In specific embodiments, the at least one on-board communication unit isone on-board communication unit and the at least one camera forrecording the section of the membrane is one camera, wherein theon-board communication unit and the camera in sum have a weight of 1 gto 300 g, preferably 1 g to 150 g, most preferably 1 g to 80 g. Thissetup further reduces the weight of the aerial drone. Few connectingparts or other heavy or expensive imaging components are required.

In specific embodiments, the at least one on-board communication unit isone single-board computer and the sum of the weight of the single-boardcomputer and of all cameras for recording the section of the membrane is1 g to 300 g, preferably 1 g to 150 g, most preferably 1 g to 80 g. Thissetup further reduces the weight of the aerial drone. Few connectingparts or other heavy or expensive imaging components are required.

In specific embodiments, the aerial drone comprises one camera forrecording a section of the membrane, but no further cameras.

In specific embodiments, one camera for recording a section of themembrane has a weight of 1 g to 20 g, preferably 1 g to 10 g.

In specific embodiments, all cameras of the aerial drone have a totalweight of 1 g to 50 g, preferably 1 g to 30 g.

In specific embodiments, the aerial drone is an octocopter.

In specific embodiments, the aerial drone has landing legs with a lengthof 15 cm to 90 cm, preferably 35 cm to 80 cm.

A further object of the invention is to provide a system for repairingholes or punctures in a membrane on a roof, which reduces the need forworkers to be on roofs and which automates the roof repair andmaintenance process.

The system comprises an aerial drone according to claims 1 to 7,preferably according to claims 2 to 7, and a ground based communicationunit adapted to wirelessly send commands for the 3D printer to theon-board communication unit of the aerial drone and/or adapted towirelessly receive recordings from the at least one camera via theon-board communication unit. The on-board communication unit and theground based communication unit are connected by a wireless network. Theground based communication unit is preferably a personal computer,laptop, or smart phone.

The combination of connected on-board communication unit and groundbased communication unit allows that recordings from the at least onecamera of the aerial drone can be sent to a ground based communicationunit. Thus, the section of the membrane can be observed before, during,and after printing. Further, the combination of connected on-boardcommunication unit and ground based communication unit allows that the3D printer can be controlled precisely from the ground basedcommunication unit. This system reduces the need for workers to be onroofs. The roof repair and maintenance method is fully or at leastpartially automated. This reduces the risk for the worker, who can workfrom the ground based communication unit.

In specific embodiments, the on-board communication unit is accessible(remotely) via the wireless network via an operating system installed onthe on-board communication unit and optionally on the ground basedcommunication unit. In specific embodiments, the wireless network is awireless hotspot generated by a smart phone. This allows a quick setupof the system by the human at the site where the membrane and roof isinstalled.

In specific embodiments, the operating system of the on the on-boardcommunication unit is Octoprint. The on-board communication unit,respectively the single-board computer or Raspberry Pi, is accessibleremotely via browser using Octoprint. Thus, it is possible to send printcommands to the on-board communication unit. Octoprint also supportssingle-board computers with camera.

In specific embodiments, the wireless network is a wireless hotspotgenerated by a smart phone and the operating system of the on theon-board communication unit is Octoprint.

A further object of the invention is to provide a method for repairingholes or punctures in a membrane on a roof, which reduces the need forworkers to be on roofs and which automates the roof repair andmaintenance process.

The method comprises the steps of detecting at least one hole orpuncture in a section of the membrane on the roof, of recording at leastthe section of the membrane with at least one camera of an aerial droneaccording to claims 1 to 7, of landing an aerial drone according toclaims 1 to 7 on the membrane on the roof such that the 3D printer ofthe aerial drone can print onto the section of the membrane, inparticular onto at least one hole or puncture, and of printing onto thesection of the membrane, in particular onto the at least one hole orpuncture, using the 3D printer and preferably printing material of theaerial drone.

The order of these steps is generally not mandatory. However, the stepof printing will be the last of these steps in most embodiments. Inparticular, the step of detecting and the step of recording may besimultaneous or the recording may take place prior to detecting.

In specific embodiments, the step of detecting at least one hole orpuncture in a section of the membrane on the roof is conducted by ahuman on the roof, by a human using an aerial drone or automatically byan aerial drone.

The step of recording at least the section of the membrane with at leastone camera of an aerial drone according to claims 1 to 7 can be done inseveral manners: In specific embodiments, the at least one camerarecords after landing of the aerial drone on the membrane on a roof. Inspecific embodiments, the at least one camera records only after landingof the aerial drone on the membrane on a roof. Preferably, the sectionhas been found to have at least one hole or puncture before landing ofthe aerial drone. For an effective use of the 3D printer, it isnecessary that the at least one camera records the section of themembrane with holes or punctures. Based on the recordings, the aerialdrone controls the printing itself or the printing is controlledexternally.

In specific embodiments, the recording of at least the section of themembrane with at least one camera is part of the flying operation of theaerial drone. This means the recordings of the camera are used forflying of the aerial drone and/or directing the aerial drone's movement.

In specific embodiments, the at least one camera for recording a sectionof the membrane records during flight of the aerial drone. Thisembodiment is useful to detect holes or punctures in a membrane on aroof.

In specific embodiments, the at least one camera for recording a sectionof the membrane records a section of the membrane on the roof betweenthe legs of the drone in landing position. Preferably, the section ofthe membrane onto which the 3D printer prints, is part of the section ofthe membrane that is recorded by the at least one camera.

In preferred embodiments, the at least one camera for recording asection of the membrane provides recordings to the at least one on-boardcommunication unit.

In preferred embodiments, the at least one camera for recording asection of the membrane provides recordings of at least the section ofthe membrane to the at least one on-board communication unit.

The step of landing an aerial drone according to claims 1 to 7 on themembrane on the roof is conducted such that the 3D printer of the aerialdrone can print onto the section of the membrane, in particular onto atleast one hole or puncture. This means that the nozzle of the 3Dprinter, which preferably is movable, can reach the section of themembrane to be printed on, in particular the at least one hole orpuncture.

In preferred embodiments, the method comprises a step at a ground basedcommunication unit of wirelessly receiving recordings of at least thesection of the membrane from at least one camera and sending commandsfor the 3D printer to the 3D printer via at least one on-boardcommunication unit of the aerial drone. The ground based communicationunit is preferably a personal computer, laptop, or smart phone. Thisstep allows that the method is precisely controlled by a human at theground based communication unit, who receives live images from theprinting site. The human has no risk of falling from the roof.

In specific embodiments, the method comprises a step at a ground basedcommunication unit of wirelessly receiving recordings of at least thesection of the membrane from at least one camera via at least oneon-board communication unit of the aerial drone. The ground basedcommunication unit is preferably a personal computer, laptop, or smartphone. This step allows that the method can be supervised by a human atthe ground based communication unit, who receives live images from theprinting site. The human has no risk of falling from the roof.

In specific embodiments, the method comprises a step at a ground basedcommunication unit of wirelessly sending commands for the 3D printer tothe 3D printer via at least one on-board communication unit of theaerial drone. The ground based communication unit is preferably apersonal computer, laptop, or smart phone.

In specific embodiments, the method comprises a step of setting up awireless network, preferably a wireless hotspot using a smart phone,between the on-board communication unit and the ground basedcommunication unit. A wireless network enables communication between theat least one on-board communication unit of the aerial drone and theground based communication unit. A wireless hotspot can be setup quicklyusing a smart phone at the site of the building with the roof in orderto enable wireless communication.

In specific embodiments, the temperature of a hot end of the 3D printeris set to 190° C. to 300° C., preferably 210° C. to 260° C., duringprinting. It has been found that this temperature is required forextrusion of specific printing materials such as (flexible) filamentfrom polyvinyl chloride.

In preferred embodiments, the method according to the invention isconducted by the aerial drone automatically or is controlled and/orsupervised by a human operator at the ground based communication unit.

In preferred embodiments, the membrane on the roof contains polyvinylchloride and/or polyurethane and/or thermoplastic olefin and/or themembrane on the roof is a liquid applied membrane.

In preferred embodiments, the membrane on the roof contains polyvinylchloride and/or polyurethane.

In preferred embodiments, the membrane on the roof is a liquid appliedmembrane.

In preferred embodiments, the membrane on the roof is a thermoplasticolefin.

In preferred embodiments, the membrane on the roof containsthermoplastic olefin.

EXAMPLE

With reference to a FIGURE, the invention will be further described inthe following.

FIG. 1 shows an aerial drone and a system according to the invention.

A CoLiDo D1315 FDM 3D printer was employed as 3D printer 5 for thisexample. The stock baseplate for the 3D printer 5 was replaced with acustom base to allow for direct to surface 3D printing. The custom baseis a circular object cut from ¼″ Plexiglas with the same diameter as theoriginal base. A large hole was cut in the center of the base to allowfor direct to surface printing. Additional holes were drilled in thecustom base to allow for the original screws to be used to attach thebase to the printer 5.

In normal operation, the 3D printing software prevents the print head 9,12 of CoLiDo D1315 FDM 3D from moving to a Z-position that is lower thanthe surface of the print area of the stock baseplate. These restrictionsare designed to prevent damage to the print head 9, 12, but make directto surface printing impossible without further modification to thesoftware or CoLiDo D1315 FDM 3D printer 5.

This issue was resolved by placing three 3D printed blocks over thescrew heads on the sliders that move the arms of the printer 5. At thetop of each leg of the printer 5 there is a switch that is pushed in bythe sliders. When all three switches are engaged the print head is inits home position. The printer 5 orients all of its movement functionsbased on its home position. Therefore, placing a block between theslider and home switch adjusts the home position to a lower Z-position.This allows one to override the lower Z-position limit and printdirectly to a surface by placing the appropriately sized block betweenthe slider and switch. Furthermore, the printer 5 can be restored to itsdefault state by removing the blocks from the sliders. Using the blocksa successful direct to surface test print was performed. As a result ofthese experiments it was confirmed that the 3D printer 5 was configuredso that it can print directly onto an existing roof 2.

For first experiments, a PLA (Polylactide) filament with a thickness of1.75 mm was used. The filament was arranged to be fed from a spool intothe CoLiDo D1315 FDM 3D printer 5.

Then, a Raspberry Pi 3 Model B as on-board communication unit 8 and aRaspberry Pi NoIR Camera V2 as camera 3 for recording a section of themembrane were connected. Mudder black aluminum heat sinks for theRaspberry Pi Model B were used.

A TONV Power Bank battery was connected via a male USB to male MicroUSBcable to the Raspberry to power the Raspberry 8. A TalentCell 12 V PowerBank battery was connected via a DC connector to power the printer 5.The Raspberry Pi 8 and the printer 5 were connected via a USB 2.0 male Ato male B cable.

A microcomputer 8 known as a Raspberry Pi was used to enable the 3Dprinter 5 to receive print commands wirelessly. The Pi 8 basically actsas a very small computer that can be attached to the printer 5 and cansend print commands via USB cable. The Pi 8 can be accessed remotely viabrowser using an operating system known as OctoPrint. Therefore it ispossible to send print commands from a browser window that is opened ona PC 7 or smart phone 7 to the Pi 8 over a Wi-Fi network. Once thecommands are received by the Pi 8 they can be executed by the printer 5to print an object.

OctoPrint was installed on the Pi 8 by downloading the program andwriting the image to an SD card. Inserting the SD card into the Pi 8allows OctoPrint to boot up upon powering up the Pi 8.

To receive print commands the Pi 8 must be connected to the samewireless network as another device such as a smart phone 7, or PC 7, orlaptop 7. This was achieved by editing a wireless access program file inOctoPrint to allow the Pi 8 to connect to the wireless hotspot generatedby an iPhone 7. Once connected, other devices connected to the samewireless hotspot (such as a PC 7 or the iPhone 7 itself) can communicatewith the Pi 8.

In order to communicate with the Pi 8 a browser window is opened and theIP address for the Pi 8 is entered into the browser. The IP address forthe Pi 8 can be determined by connecting the Pi 8 to a monitor using anHDMI cable, powering up the Pi 8 and logging in using a keyboardconnected to the Pi 8. The IP address will be displayed on the monitor.Once the correct IP address is entered, the interface for OctoPrint willload in the browser window. From here g-code files can be uploaded andprint commands can be given wirelessly. OctoPrint also supports theRaspberry Pi camera 3 and can provide a live feed of the print job. Todemonstrate the wireless printing capabilities a small Sika logo wassuccessfully printed.

Once it was confirmed that the printer 5 could successfully receiveprint commands wirelessly the range of the wireless connection wasdetermined. The printer 5 was placed outside and the Pi 8 and a laptop 7were connected to the wireless hotspot generated by an iPhone 7. TheiPhone 7 and the laptop were then moved away from the printer 5. The Pi8 was still connected to the wireless network when it was approximately200 ft. away from the iPhone 7. A test print was performed at a range ofapproximately 100 feet and was successful.

As a result of these experiments it was confirmed that the 3D printer 5is able to receive print commands wirelessly.

Batteries were used to power the 3D printer 5 so that it could operatewithout being connected to any stationary power sources. This wasachieved by acquiring a battery capable of powering the printer 5 andone to power the Pi 8 (and the Pi camera 3). The batteries were attachedto the printer 5 with Velcro and were used to power the respectivedevices. A test print was successfully performed using the batteries asa power source. Used in conjunction with the wireless printingcapability, the battery power provides mobility to the 3D printer 5 thatis required for its use as a component of a 3D printer drone 1.

As a result of these experiments it was confirmed that the 3D printer 5can be battery powered.

In order to repair damage to PVC membrane it is necessary to patch thedamaged area with new flexible PVC, or some other compatible materialsuch as the polyurethanes used in the liquid applied membranes.Polylactide (PLA) can also be an option in certain cases.

As an aerial drone a DJI Spreading Wings 51000+ drone with DJI A2 flightcontrol system Futaba T14SG radio controller, Tattu 22000 mAh 6C LiPobattery, MaxAmps 24 V power supply, Hyperion EOS 0840i 1000 W charger,and CineMilled DJI S1000/Ronin-M Extended Carbon Fiber Landing Gear wasemployed in this example.

To the bottom of the aerial drone the above modified CoLiDo D1315 FDM 3Dprinter 5 was attached. The printer was attached to the gimbal mount ofthe drone using heavy duty cable ties. Two cable ties were wrappedaround each of the three legs of the printer and the gimbal mountingbase. The ties were tightened as much as possible and the printer wasfound to be tightly attached. A mechanism such as screwing the top plateof the 3D printer to the gimbal mounting base may also be employed. Allother components were attached as well using standard means such asVelcro, glue, etc. According to the manual for the DJI Spreading Wings51000+ drone, the maximum takeoff weight for the drone is 11 kg.

The takeoff weight of the drone 1 fully loaded with the modified 3Dprinter, battery, and all other components is just about 11 kg. A 22000mAh battery was attached to the drone such that it powers the motors ofthe drone 1. A test flight was successfully performed with a takeoffweight of the drone of about 9 kg. After about 8 minutes of flight time,less than half of the battery power was consumed. Therefore, it has beenshown that the drone is powerful enough to lift the modified 3D printer5 and all required components with an optimized weight for a sufficientamount of time in order to repair the membrane on a roof.

In summary, the inventors have developed means, i.e. a drone 1, a system8, and a method 10, for repairing holes or punctures in a membrane on aroof 2, which reduce the need for workers to be on roofs and whichautomate the roof repair and maintenance process.

REFERENCE NUMBER LIST

-   1 aerial drone according to the invention-   2 roof (with membrane)-   3 camera-   4 section of the membrane-   5 3D printer-   6 ground-   7 ground based communication unit-   8 on-board communication unit-   9 hot end (of 3D printer)-   10 system according to the invention-   11 leg of the drone (landing position)-   12 nozzle (of 3D printer)

1. An aerial drone for repairing holes or punctures in a membrane on aroof, wherein the aerial drone comprises at least one camera forrecording a section of the membrane, a 3D printer adapted to print ontothe section of the membrane, wherein the 3D printer is controllablewirelessly from a different altitude and/or the ground.
 2. The aerialdrone according to claim 1, wherein the aerial drone comprises at leastone on-board communication unit, wherein the at least one on-boardcommunication unit is adapted to wirelessly receive commands for the 3Dprinter from a ground based communication unit and/or to transfer thecommands to the 3D printer and/or wherein the at least one on-boardcommunication unit is adapted to receive recordings from the at leastone camera and to wirelessly send the recordings to a ground basedcommunication unit
 3. The aerial drone according to claim 1, wherein the3D printer is a fused deposition modeling 3D printer, which iscontrolled wirelessly from a different altitude and/or the ground. 4.The aerial drone according to claim 1, wherein the aerial dronecomprises printing material.
 5. The aerial drone according to claim 1,wherein the aerial drone comprises printing material containingpolyvinyl chloride and/or polyurethane.
 6. The aerial drone according toclaim 1, wherein the aerial drone has a weight of 1 kg to 25 kg and/orthe aerial drone comprises at least one battery unit with a sum ofelectric charge of 14000 mAh to 30000 mAh for providing power to atleast one motor of the drone.
 7. The aerial drone according to claim 2,wherein the at least one on-board communication unit is one single-boardcomputer and the sum of the weight of the single-board computer and ofall cameras for recording the section of the membrane is 1 g to 300 g.8. A system for repairing holes or punctures in a membrane on a roof,wherein the system comprises an aerial drone according to claim 1, and aground based communication unit adapted to wirelessly send commands forthe 3D printer to the on-board communication unit of the aerial droneand/or adapted to wirelessly receive recordings from the at least onecamera via the on-board communication unit, wherein the on-boardcommunication unit and the ground based communication unit are connectedby a wireless network.
 9. The system according to claim 8, wherein thewireless network is a wireless hotspot generated by a smart phone.
 10. Amethod for repairing holes or punctures in a membrane on a roofcomprising the steps: detecting at least one hole or puncture in asection of the membrane on the roof; recording at least the section ofthe membrane with at least one camera of an aerial drone according toclaim 1; landing the aerial drone on the membrane on the roof such thatthe 3D printer of the aerial drone can print onto the section of themembrane, in particular onto at least one hole or puncture; printingonto the section of the membrane.
 11. The method according to claim 10,comprising at a ground based communication unit wirelessly receivingrecordings of at least the section of the membrane from at least onecamera and sending commands for the 3D printer to the 3D printer via atleast one on-board communication unit of the aerial drone.
 12. Themethod according to claim 11, comprising setting up a wireless networkbetween the on-board communication unit and the ground basedcommunication unit.
 13. The method according to claim 10, wherein thetemperature of a hot end of the 3D printer is set to 190° C. to 300° C.during printing.
 14. The method according to claim 10, wherein themethod is conducted by the aerial drone automatically or is controlledand/or supervised by a human operator at the ground based communicationunit.
 15. The aerial drone according to claim 1, wherein the membrane onthe roof contains polyvinyl chloride and/or polyurethane and/orthermoplastic olefin and/or the membrane on the roof is a liquid appliedmembrane.
 16. A system for repairing holes or punctures in a membrane ona roof, wherein the system comprises an aerial drone according to claim2, and a ground based communication unit adapted to wirelessly sendcommands for the 3D printer to the on-board communication unit of theaerial drone and/or adapted to wirelessly receive recordings from the atleast one camera via the on-board communication unit, wherein theon-board communication unit and the ground based communication unit areconnected by a wireless network.
 17. The system according to claim 8,wherein the membrane on the roof contains polyvinyl chloride and/orpolyurethane and/or thermoplastic olefin and/or the membrane on the roofis a liquid applied membrane.
 18. The method according to claim 10,wherein the membrane on the roof contains polyvinyl chloride and/orpolyurethane and/or thermoplastic olefin and/or the membrane on the roofis a liquid applied membrane.